SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a48af5a925cdceed0ec14783091c1f4fce0256e689a5735280fab54c5eec4611' 
  AND token = 'eMpxOMQeitBUnIIaZKBetGEkynRTelkJv90xNtcM9Gs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}